As with any local anaesthetic, the safety and effectiveness of lidocaine depend on the proper dosage, the correct technique, adequate precautions and readiness for emergencies.
The following dosage recommendations should be regarded as a guide. The clinician's experience and knowledge of the patient's physical status are of importance in calculating the required dose.
Urethral Anaesthesia: Surface Anaesthesia of the Male Adult Urethra: For adequate analgesia in males, 20 mL (lidocaine HCl 400 mg) jelly is required. The jelly is instilled slowly until the patient has a feeling of tension or until almost ½ the tube (10 mL=lidocaine HCl 200 mg) has been emptied.
A penile clamp is then applied for several minutes at the corona, after which the rest of the jelly is instilled.
When anaesthesia is especially important eg, during sounding or cystoscopy, a larger quantity of jelly (30-40 mL) may be instilled in 3-4 portions and allowed to act for 10-12 min before insertion of the instrument. The jelly instilled into the bladder is also effective procedures in this region.
Surface Anaesthesia of the Female Adult Urethra: Instil 5-10 mL in small portions to fill the whole urethra. In order to obtain adequate anaesthesia, several minutes should be allowed to elapse prior to performing urological procedures.
Endoscopy: The instillation of 10-20 mL is recommended for adequate analgesia and a small amount may be applied to the lubricating instrument. When combined with other lidocaine products (eg, bronchoscopy), the total dose of lidocaine should not exceed 400 mg.
Proctoscopy and Rectoscopy: Up to 20 mL can be used for anal and rectal procedures. The total dose should not exceed 400 mg lidocaine.
Lubrication for Endotracheal Intubation: About 2 mL applied to the surface of the tube just prior to insertion. Care should be taken to avoid introducing Xylocaine Jelly into the lumen of the tube.
Children <12 years: The dose should not exceed 6 mg/kg.
Debilitated or elderly patients, children >12 years, acutely ill patients or patients with sepsis should be given doses commensurate with their age, weight and physical condition.
Note: No more than 4 doses should be given in a 24-hr period. After use, the jelly is no longer sterile and should be discarded.